Nitrogen-containing heterocyclic ring derivatives and analgesic and anti-inflammatory compositions and methods employing them

ABSTRACT

Novel nitrogen-containing heterocyclic compounds shown by the formula ##STR1## wherein one of R 1  and R 2  represents a lower alkyl group, a phenyl group, a halophenyl group, or a lower alkoxyphenyl group and the other of them represents a hydrogen atom, a lower alkyl group, or a phenyl lower alkyl group; said R 1  and R 2  may combine with each other to form a trimethylene group or a tetramethylene group; R 3  represents a hydrogen atom, a lower alkyl group, a phenyl group, or a phenyl lower alkyl group; X represents an oxygen atom, a sulfur atom, an imino group, or a group shown by ##STR2## (wherein m represents 1 or 2 and R 4  represents a lower alkyl group, a hydroxy lower alkyl group, a cycloalkyl group or a phenyl lower alkyl group); and Y represents an ethylene group which may be substituted by lower alkyl group, a trimethylene group, a tetramethylene group, a vinylene group which may be substituted by a lower alkyl group, or ##STR3## (wherein R 5  represents a hydrogen atom, a lower alkyl group, a trifluoromethyl group, or a phenyl group); said X is the group shown by ##STR4## when one of said R 1  and R 2  is a lower alkyl group and the other is a hydrogen atom, and said Y is an ethylene group, and the pharmacologically acceptable non-toxic salts thereof. 
     The compounds described above are strong analgesic anti-inflammatory agents.

This application is a divisional application of U.S. patent application Ser. No. 876,517, filed Feb. 9, 1978, which is a continuation-in-part application of U.S. Ser. No. 814,325, filed July 11, 1977, now abandoned.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to novel nitrogen-containing heterocyclic compounds. More particularly, the invention relates to the nitrogen-containing heterocyclic compounds shown by formula I ##STR5## wherein one of R₁ and R₂ represents a lower alkyl group, a phenyl group, a halophenyl group, or a lower alkoxyphenyl group and the other of them represents a hydrogen atom, a lower alkyl group, or a phenyl lower alkyl group; said R₁ and R₂ may combine with each other to form a trimethylene group or a tetramethylene group; R₃ represents a hydrogen atom, a lower alkyl group, a phenyl group, or a phenyl lower alkyl group; X represents an oxygen atom, a sulfur atom, an imino group, or a group shown by ##STR6## (wherein m represents 1 or 2 and R₄ represents a lower alkyl group, a hydroxy lower alkyl group, a cycloalkyl group or a phenyl lower alkyl group); and Y represents an ethylene group which may be substituted by a lower alkyl group, a trimethylene group, a tetramethylene group, a vinylene group which may be substituted by lower alkyl group, or ##STR7## (wherein R₅ represents a hydrogen atom, a lower alkyl group, a trifluoromethyl group, or a phenyl group); said X is the group shown by ##STR8## when one of said R₁ and R₂ is a lower alkyl group and the other is a hydrogen atom, and said Y is an ethylene group, and the pharmacologically acceptable non-toxic salts thereof.

The compounds of this invention shown by formula I have very strong antiinflammatory activity and also strong analgesic activity, and hence are novel and useful compounds expected as strong analgesic anti-inflammatory agents.

The definitions of the terms used in the specification and the claims of this invention are as follows:

That is, "lower alkyl group" is a straight or branched chain alkyl group having 1-6 carbon atoms and includes, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an amyl group, an isoamyl group, and a n-hexyl group. "Lower alkoxy group" is a straight or branched chain alkoxy group having 1-6 carbon atoms and includes, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a n-butoxy group, an amyloxy group, and a n-hexyloxy group. "Cycloalkyl group" is a cycloalkyl group having 5-7 carbon atoms and includes a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. "Halogen atom" includes a fluorine atom, chlorine atom, bromine atom, and an iodine atom. "Phenyl lower alkyl group" is a lower alkyl group substituted by a phenyl group and includes, for example, a benzyl group and a phenetyl group.

The compounds I of this invention have a feature of chemical structure in the point that the 1-position and the 6-position of 2-pyridone are cyclized by a hetero-atom and an alkylene group and it has not hitherto been known that such nitrogen-containing heterocyclic compounds have excellent anti-inflammatory activity. In addition, in regard to such nitrogen-containing heterocyclic compounds, 7-methyl-5-oxo, 7,8-dimethyl-5-oxo- and 7-methyl-8-phenyl-5-oxo-1,2,3,5-tetrahydroimidazo[1,2-]pyridine are described in "Yakaguaku Zasshi"; 91(11), 1174-1177(1971) and also 7-methyl-5-oxo-2,3,5-trihydrothiazolo[3,2-a]pyridine is disclosed in "Chem. Ber."; 86, 468(1953). However, the the use of these compounds as medicaments is not reported in these literatures.

The preferred homologues of this invention are the nitrogen-containing heterocyclic compounds of formula I wherein one of R₁ and R₂ represents a lower alkyl group, a phenyl group, a halophenyl group or a lower alkoxyphenyl group and the other of them represents a hydrogen atom or a lower alkyl group; said R₁ and R₂ may combine with each other to form a trimethylene group or a tetramethylene group; R₃ represents a hydrogen atom; X represents an oxygen atom, a sulfur atom, an imino group, ##STR9## (wherein m represents 1 or 2 and R₄ ' represents a lower alkyl group, a cycloalkyl group or a phenyl lower alkyl group); and Y represents an ethylene group which may be substituted by a lower alkyl group, a trimethylene group, a tetramethylene group, or a vinylene group which may be subsituted by a lower alkyl group; and X is the groups shown by ##STR10## when one of said R₁ and R₂ is a lower alkyl group and the other of them is a hydrogen atom and said Y is an ethylene group.

One example of the more preferred homologeus of the above-described homologues is the nitrogen-containing heterocyclic compounds of formula I wherein R₁ and R₃ are hydrogen atoms; R₂ is a phenyl group, a halophenyl group, or a lower alkoxyphenyl group; X is an imino group or the group shown by ##STR11## and Y is an ethylene group or a trimethylene group. Another example of the more preferred homologues is the nitrogen-containing heterocyclic compounds of formula I wherein one of R₁ and R₂ is a phenyl group and the other of them is a hydrogen atom; R₃ is a hydrogen atom; X is the group shown by ##STR12## (wherein m is 1 or 2 and R₄ ' is a lower alkyl group); and Y is an ethylene group; said X is the group shown by ##STR13## when R₁ is a phenyl group and R₂ is a hydrogen atom.

A further example of the more preferred homologues is the nitrogen-containing heterocyclic compounds of formula I wherein R₁ and R₃ are hydrogen atoms; R₂ is a lower alkyl group; X is an imino group or the group shown by ##STR14## (wherein R₄ ' is a lower alkyl group); and Y is an ethylene group or a trimethylene group; said X is the group shown by ##STR15## when Y is an ethylene group.

A still further example of the more preferred homologues is the nitrogen-containing heterocyclic compounds of formula I wherein R₁ and R₂ combines with each other to form a trimethylene group or a tetramethylene group; R₃ is a hydrogen atom; X is an oxygen atom, a sulfur atom, an imino group, or the group shown by ##STR16## (wherein R₄ ' is a lower alkyl group); and Y is an ethylene group or a trimethylene group. A still other example of the more preferred homologues is the nitrogen-containing heterocyclic compounds of formula I wherein one of R₁ and R₂ is a phenyl group and the other of them is a lower alkyl group; R₃ is a hydrogen atom; X is the group shown by ##STR17## and Y is an ethylene group, a trimethylene group, or a tetramethylene group. Another example of the more preferred homologues is the nitrogen-containing heterocyclic compounds of formula I wherein one of R₁ and R₂ is a lower alkyl group, a phenyl group, a halophenyl group or a lower alkoxyphenyl group, and the other of them is a hydrogen atom or a lower alkyl group, said R₁ and R₂ may combine each other to form a trimethylene group or a tetramethylene group; R₃ is a hydrogen atom; X is an oxygen atom, a sulfur atom, an imino group or the group shown by ##STR18## (wherein m represents 1 or 2 and R₄ ' is a lower alkyl group, a cycloalkyl group or a phenyl lower alkyl group); Y is an ethylene group substituted by a lower alkyl group or a vinylene group which may be substituted by a lower alkyl group.

Examples of the particularly preferred compounds of this invention are 5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a] pyridine, 1-methyl-6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido [1,2-a] pyrimidine and 1,7-dimethyl-5-oxo-1,2,3,5-tetrahydroimidazo [1,2-a] pyridine.

As the pharmacologically acceptable non-toxic salts of the compounds of this invention shown by formula I, there are the addition salts with an acid such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, etc.

The compounds of this invention shown by formula I are prepared;

(a) by reacting the 2-pyridone derivative shown by formula II ##STR19## wherein R₁,R₂ and R₃ have the same meaning as above and W represents a hydrogen atom, a phenyl group, a halophenyl group, a trifluoromethylphenyl group, or a lower alkylphenyl group, with the amine derivative shown by formula III

    NH.sub.2 --Y--X--H                                         III

wherein X and Y have the same meaning as above;

(b) by reacting the compound shown by formula IV ##STR20## wherein R₁, R₂ and R₃ have the same meaning as above; A represents a cyano group or a carboxy group; B represents a halogen atom, a hydroxyl group or a lower alkoxy group; and the dotted lines show that one of them is a double bond; said B represents a hydroxyl group when said A is a carboxy group, with the amine derivative shown by formula III

    NH.sub.2 --Y--X--H                                         III

wherein X and Y have the same meaning as above; or

(c) by heating the 2-pyridone derivative shown by formula V ##STR21## wherein R₁, R₂, R₃, X and Y have the same meaning as above, in the presence of a base.

Practically speaking, process (a) is carried out by reacting the compound of formula II with an equimolar amount or an excessive amount of the compound of formula III in an organic solvent which does not participate in the reaction, such as methanol, ethanol, 2-ethoxyethanol, diglyme, dichlorobenzene, xylene, dimethylformamide, etc. The reaction is performed with heating, that is, performed at a temperature of about the boiling point of the solvent used or at a temperature above the boiling point of the solvent in a sealed tube but, preferably performed under refluxing with heating. This reaction may be performed in the presence of a base such as potassium carbonate, sodium carbonate, potassium hydrogencarbonate, sodium hydrogencarbonate, etc. Furthermore, the compound of formula III may be supplied to the reaction system as an addition salt with an acid such as acetic acid, etc.

Process (b) is performed by reacting the compound of formula IV with an equimolar amount or an excessive amount of the compound of formula III in an organic solvent which does not participate in the reaction, such as methanol, ethanol, ether, 2-ethoxyethanol, diglyme, xylene, ethyleneglycol, dichlorobenzene, etc. The reaction is preferably performed with heating, that is, performed at a temperature of about the boiling point of the solvent used or at a temperature above the boiling point of the solvent in a sealed tube. The reaction is usually performed under refluxing with heating. Also, the compound of formula III may be supplied to the reaction system as the acid addition salt with an acid such as acetic acid, etc.

Process (c) is performed by heating the compound of formula V in an organic solvent which does not participate in the reaction, such as methanol, ethanol, ether, 2-ethoxyethanol, diglyme, dichlorobenzene, xylene, dimethylformamide, etc., in the presence of a base. The reaction is performed with heating, that is, performed at a temperature of about the boiling point of the solvent used or at a temperature above the boiling point of the solvent in a sealed tube. The reaction is preferably performed under refluxing with heating. The reaction is performed in the presence of a base such as sodium hydride, sodium methoxide, sodium ethoxide, potassium carbonate, sodium carbonate, potassium hydrogencarbonate, sodium hydrogencarbonate, etc.

Now, the compounds I of this invention wherein X is the group shown by ##STR22## and Y is an ethylene group which may be substituted by lower alkyl group or a vinylene group which may be substituted by lower alkyl group, that is, the compounds of this invention shown by formula Ia ##STR23## wherein R₁, R₂, R₃, and m have the same meaning as above and Z represents an ethylene group which may be substituted by lower alkyl group or a vinylene group which may be substituted by lower alkyl group, are produced by oxidizing the compounds shown by formula Ib ##STR24## wherein R₁, R₂, R₃, and Z have the same meaning as above. Practically speaking, the reaction is performed by dissolving the compound of formula Ib in an acid such as acetic acid, etc., and oxidizing the compounds with an oxidizing agent such as hydrogen peroxide at room temperature or under heating. Hydrogen peroxide is usually used as a 10-30% aqueous hydrogen peroxide solution. In this case, by properly selecting the reaction conditions such as the reaction time, the reaction temperature, the amount of the oxidizing agent used, etc., the desired monoxide compound (m=1) or the desired dioxide compound (m=2) can be obtained.

Also, the compounds of this invention shown by formula I wherein X is a sulfur atom and Y is a vinylene group which may be substituted by lower alkyl group, that is, the compounds of this invention shown by formula Ic ##STR25## wherein R₁, R₂ and R₃ have the same meaning as above and R₆ represents a hydrogen atom or a lower alkyl group, can be produced by reacting the compound shown by formula Id ##STR26## wherein R₁, R₂, R₃, and R₆ have the same meaning as above with an acylating agent such as acetic anhydride, etc., to form the compound shown by formula Ie ##STR27## wherein R₁, R₂, R₃, and R₆ have the same meaning as above and then treating the compound of formula Ie with an acid. The acid treatment can be performed at room temperature using an acid such as concentrated sulfuric acid, phosphoric acid, etc. In this case, a solvent such as ethanol, etc., may be used.

Furthermore, the compounds of this invention shown by formula I wherein X is the group shown by ##STR28## that is, the compounds of this invention shown by formula If ##STR29## wherein R₁, R₂, R₃, R₄ and Y have the same meaning as above, can be produced by reacting the compound shown by formula Ig ##STR30## wherein R₁, R₂, R₃ and Y have the same meaning as above, with an equimolar amount or excessive amount of the compound shown by formula VI

    halogen-R.sub.4                                            VI

wherein R₄ has the same meaning as above, in an organic solvent which does not participate in the reaction, such as methanol, ethanol, isopropanol, 2-ethoxyethanol, diglyme, dimethylformamide, etc. This reaction is preferably performed in the presence of a base such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, etc. In the case of using such a base, it is suitable to use a aqueous organic solvent as the reaction solvent. Also, the reaction can be performed in the presence of a base such as sodium hydride, sodium methoxide, sodium ethoxide, etc., and in the case of using such a base, the reaction is usually performed in an organic solvent such as dimethylformamide, etc., as the reaction solvent. Furthermore, the reaction may proceed without heating but the reaction is usually performed with heating.

The compounds of this invention shown by formula I can be produced by the various methods as described above but as shown in the examples described below, they can also be produced by other methods than above.

The compounds of this invention shown by formula I thus produced can be isolated and purified by an ordinary chemical operation such as concentration, recrystallization, column chromatography, etc.

Then, the results of the following experiments show the excellent therapeutical activities of the compounds of this invention:

(a) Carrageenin-induced edema

Male Wister rats (weighting 130-170 g.), one group being 6 rats, fasted overnight were used. According to Wister's method [Proc. Soc. Exp. Biol. Med., 111,544 (1962)], 0.1 ml. of 1% Carrageenin [Iwai Kagaku Yakuhin K.K. Seakem] suspension in 0.9% saline was injected into the planter tissue of the left hind paw. After 3 hours, each rat was sacrificed by chloroform and the hind paw was cut and weighed immediately. By using the value obtained by subtracting the weight of the untreated hind paw from the weight of the hind paw having injected therein the Carrageenin as the weight of edema, the inhibitory ratio of the sample administered rat groups to control groups was calculated. The sample was orally administered one hour before the injection of Carrageenin. The results obtained are shown in Table 1.

(b) Whittle's method (British J. Pharmacol.; 22, 246-253 (1964))

Male ICR-Mice (weighting 25-35 g.), one group being 12 mice, fasted overnight were used in this test. The sample was orally administered, and 20 minutes after, 5 ml./Kg. of 0.4% Evance blue was injected by intravenously and further 10 minutes after, 10 ml./Kg. of 0.6% acetic acid was injected by intraperitoneally. The number of writhings after 20 minutes since the administration of acetic acid was recorded and 10 minutes after since then, the mice were killed by dislocation of the neck, the dye leaked in the abdominal cavity was washed out with 5 ml. of 0.9% saline to make the total amount 10 ml., and thereafter furs, blood corpuscles, etc., intermingled were removed by centrifugal separation at 3,000 r.p.m. for 5 minutes. Furthermore, for preventing turbidity caused by protein, 0.1 ml. of an aqueous 0.1 normal sodium hydroxide was added and then the absorbance at 590 nm was measured. The inhibition ratio of the sample administered rat groups to control groups was calculated. The results are shown in Table 2.

(c) Antipyretic effect

Male Wister rats (weighting 130-150 g.), one group being 5 rats, were used. Hyperthemia was caused by subcutaneous injection of 2 ml./rat of 20% Brewer's yeast suspension. 18 hours later, the rats showing a rise in temperature exceeding 1° C. were selected and allocated into groups each consisting of 5 rats. The sample was orally administered and then the body temperature was measured with the passage of time for 6 hours since then. In addition, the body temperature was measured by measuring the temperature in the rectum by means of a thermister thermometer. The results are shown in Table 3.

(d) Acute toxicity

Male Wister rats (weighting 130-170 g.), one group being 5 rats, fasted overnight were used in this test. After orally administering 500 mg./Kg. of a sample, they were observed for 7 days to determine whether they were living or dead. The results are shown in Table 4.

In addition, the test samples used in the aforesaid tests (a), (b), (c) and (d) were prepared by suspending the test compounds, in the cases of using the compounds of Test Nos. 1,2,4,5,6,8,9,10,11, 16-21 and p henylbutazone, in an aqueous 0.5% methyl cellulose solution, dissolving the test compounds, in the cases of using the compounds of Test Nos. 13,14 and 15, in aqueous solution of 0.5% methyl cellulose, and further dissolving the test compounds, in the cases of using the compounds of Test Nos. 3,7 and 12 and aminopyrine, in distilled water.

                                      TABLE 1                                      __________________________________________________________________________      ##STR31##                                                                     Sample                                 Inhibition (%) p.o.                     Test No.                                                                            R.sub.1                                                                             R.sub.2  R.sub.3                                                                               X      Y     50mg/kg                                                                             100mg/kg                           __________________________________________________________________________     1    H                                                                                    ##STR32##                                                                              H                                                                                    ##STR33##                                                                            (CH.sub.2).sub.3                                                                       71.5 --                                 2    H                                                                                    ##STR34##                                                                              H                                                                                    ##STR35##                                                                            (CH.sub.2).sub.2                                                                       71.6 76.1                               3    H    CH.sub.3 H                                                                                    ##STR36##                                                                            (CH.sub.2).sub.2                                                                       52.3 51.5                               4    H                                                                                    ##STR37##                                                                              H                                                                                    ##STR38##                                                                            (CH.sub.2).sub.2                                                                       70.2 --                                 5    H                                                                                    ##STR39##                                                                              H                                                                                    ##STR40##                                                                            (CH.sub.2).sub.2                                                                       69.2 77.3                               6    H                                                                                    ##STR41##                                                                              H                                                                                    ##STR42##                                                                            (CH.sub.2).sub.3                                                                       72.7 80.5                                     ##STR43##                                                                          H        H                                                                                    ##STR44##                                                                            (CH.sub.2).sub.2                                                                       75.0 79.5                               8    H    CH.sub.3 H                                                                                    ##STR45##                                                                            (CH.sub.2).sub.3                                                                       53.3 --                                 9    H                                                                                    ##STR46##                                                                              H                                                                                    ##STR47##                                                                            (CH.sub.2).sub.2                                                                       51.4 69.8                               10   H                                                                                    ##STR48##                                                                              H                                                                                    ##STR49##                                                                            (CH.sub.2).sub.2                                                                       --   69.0                               11   H                                                                                    ##STR50##                                                                              H                                                                                    ##STR51##                                                                            (CH.sub.2).sub.3                                                                       47.1 --                                 12   H                                                                                    ##STR52##                                                                              H                                                                                    ##STR53##                                                                            (CH.sub. 2).sub.2                                                                      --   72.8                               13   (CH.sub.2).sub.3                                                                             H                                                                                    ##STR54##                                                                            (CH.sub.2).sub.2                                                                       57.1 --                                 14   (CH.sub.2).sub.4                                                                             H                                                                                    ##STR55##                                                                            (CH.sub.2).sub.2                                                                       64.1 --                                 15   (CH.sub.2).sub.4                                                                             H                                                                                    ##STR56##                                                                            (CH.sub.2).sub.3                                                                       52.4 --                                 16                                                                                   ##STR57##                                                                          CH.sub.3 H                                                                                    ##STR58##                                                                            (CH.sub.2).sub.2                                                                       47.7 --                                 17   CH.sub.3                                                                             ##STR59##                                                                              H                                                                                    ##STR60##                                                                            (CH.sub.2).sub.3                                                                       45.7 --                                 18   H    CH.sub.3                                                                                 ##STR61##                                                                           ##STR62##                                                                            (CH.sub.2).sub.2                                                                       --   41.0                               19   H    CH.sub.3                                                                                 ##STR63##                                                                           ##STR64##                                                                            (CH.sub.2).sub.3                                                                       --   46.7                               20   H                                                                                    ##STR65##                                                                              H                                                                                    ##STR66##                                                                             ##STR67##                                                                             72.2 --                                 21   H                                                                                    ##STR68##                                                                              H                                                                                    ##STR69##                                                                            CHCH    46.9 --                                 phenylbutazone                         44.5 51.2                               __________________________________________________________________________

                  TABLE 2                                                          ______________________________________                                                    Inhibition (%)                                                                 Writhing S  Permeability                                                         25mg/kg  50mg/kg  25mg/kg                                                                               50mg/kg                                  Sample       p.o.     p.o.     p.o.   p.o.                                     ______________________________________                                         Compound of                                                                    Test No. 1   41.8     87.6     18.0   44.4                                     Compound of                                                                    Test No. 2   28.9     52.6     26.9   51.1                                     Compound of                                                                    Test No. 3   52.1     75.3     18.5   46.2                                     Compound of                                                                    Test No. 5   41.2     67.4     20.0   42.1                                     Compound of                                                                    Test No. 6   69.0     91.5     28.4   59.0                                     Compound of                                                                    Test No. 7   59.1     95.3     49.3   63.8                                     Compound of                                                                    Test No. 8   35.6     66.4     32.4   25.8                                     Aminopyrine  29.6     58.1     28.5   41.7                                     ______________________________________                                    

                                      TABLE 3                                      __________________________________________________________________________            Dose Rectal temperature (mean ± SE)                                  Sample (p.o.)                                                                              before 1 hour 2 hours                                                                               4 hours                                                                               6 hours                                __________________________________________________________________________     Compound of        *      *      *                                             Test No. 1                                                                            50mg/kg                                                                             38.82 ± 0.05                                                                       37.07 ± 0.15                                                                       36.17 ± 0.32                                                                       36.12 ± 0.17                                                                       38.52 ± 0.47                        Compound of        *      *      *      *                                      Test No. 2                                                                            50mg/kg                                                                             38.89 ± 0.21                                                                       37.80 ± 0.10                                                                       36.74 ± 0.24                                                                       36.77 ± 0.39                                                                       37.51 ± 0.57                                           *      *      *      *                                      Aminopyrine                                                                           50mg/kg                                                                             39.24 ± 0.14                                                                       37.92 ± 0.09                                                                       37.49 ± 0.10                                                                       37.39 ± 0.07                                                                       37.76 ± 0.18                        0.9% saline                                                                           10ml/kg                                                                             39.06 ± 0.16                                                                       37.56 ± 0.32                                                                       39.28 ± 0.23                                                                       39.11 ± 0.16                                                                       39.31 ± 0.19                        __________________________________________________________________________      *:significantly different from the temperature before administration           (p<0.05)                                                                 

                  TABLE 4                                                          ______________________________________                                                         Number of deaths                                               Sample No.        Rat        Mouse                                             ______________________________________                                         Compound of Test No. 1                                                                           2/5        --                                                Compound of Test No. 2                                                                           0/5        0/5                                               Compound of Test No. 3                                                                           0/5        1/5                                               Compound of Test No. 4                                                                           2/5        1/5                                               Compound of Test No. 9                                                                           0/5        0/5                                               Compound of Test No. 10                                                                          0/5        0/5                                               ______________________________________                                    

From the test results by the aforesaid Carrageenin-induced edema and Wittle's method, it is clear that the compounds I of this invention have excellent anti-inflammatory activity and excellent analgesic activity. Furthermore, from the results by the antipyretic effect, it is also clear that the compounds of this invention shown by formula I have excellent antipyretic activity.

The clinical doses of the compounds I of this invention are usually 100-1,000 mg., preferably 150-600 mg. per day for an adult and the medicament is administered by 2-3 times per day. The doses are properly controlled according to the condition and age of the patient.

The compounds of this invention are administered as various forms such as agents for oral administration, injections, suppositories for rectal administration, medicines for topical application, etc.

The medicaments of this invention are used as compositions prepared by blending with conventional pharmaceutical carriers or excipients by ordinary method. The tablets, capsules, granules, powders, etc., of the compounds of this invention for oral administration may contain an pharmaceutical excipient generally used in the field of art, such as calcium carbonate, calcium phosphate, starch, sucrose, lactose, talc, magnesium stearate, gelatin, polyvinyl pyrrolidone, gum arabic, sorbitol, microcrystalline cellulose, polyethylene glycol, silica, sodium laurylsulfate, etc. Moreover, the tablets may be coated by a manner well known in the art.

Furthermore, the liquid formulations for oral administration may be an aqueous or oily suspeison, a syrup, an elixir, etc., and are prepared by a conventional method.

Suppositories for rectal use are used and they may contain a formulation carrier well known in the art, such as polyethylene glycol, lanolin, cacao butter, Witepsol® (made by Dynamite Nobel Co.), etc.

Then, examples of the formulations of the medicaments of this invention are shown below:

Fomrulation example 1:

Tablets containing the compounds of this invention shown by formula I, the weight of one tablet being 300 mg.

    ______________________________________                                         Compound of formula I  1,000 g.                                                Lactose                1,200 g.                                                Starch                 770 g.                                                  Magnesium stearate     30 g.                                                   ______________________________________                                    

A 10% starch paste was prepared using a part of starch described above and after adding the starch paste as a binder to a mixture of the compounds of formula I, lactose and remaining starch, the resultant mixture was granulated by a conventional manner. Then, magnesium stearate was added to the granules and the mixture was molded into 10,000 tablets each having a diameter of 9.5 mm. and weight of 300 mg. The active component was 100 mg./tablet.

Formulation example 2:

Capsules containing the compounds I of this invention, the weight of one capsule being 300 mg.

    ______________________________________                                         Compound of formula I  1,000 g.                                                Lactose                1,200 g.                                                Starch                 770 g.                                                  Magnesium stearate     30 g.                                                   ______________________________________                                    

After mixing well 1,000 g. of the compound of formula I,

1,200 g. of lactose, 770 g. of starch, and 30 g. of magnesium stearate, the mixture was filled in 10,000 capsules. The weight of each capsule filled with the mixture was 300 mg. The active component was 100 mg./capsule.

EXAMPLE 1

In 6 ml. of xylene were refluxed 2 g. of 6-chloro-1-p-chlorophenyl-4-phenyl-2-pyridone and 2 g. of N-methylethylenediamine for 24 hours. After cooling the reaction mixture, 5 ml. of water was added to the reaction mixture, the pH thereof was adjusted to 1 by adding concentrated hydrochloric acid, and crystals thus precipitated were recovered by filtration. The crystals were washed successively with 10 ml. of ethyl acetate and 10 ml. of water and then recrystallized from 10 ml. of water to provide a crude hydrochloride salt. After adding thereto 30 ml. of water followed by heating to dissolve the hydrochloride salt, the solution was alkalified by adding sodium carbonate with stirring and then extracted twice each time with 10 ml. of chloroform. The extracts were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue obtained was recrystallized twice from ethyl acetate to provide 0.5 g. of 1-methyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 159° C.

Elemental analysis for C₁₄ H₁₄ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.31%     6.24%        12.38%                                     Found:      74.02%     6.09%        12.05%                                     ______________________________________                                    

In 20 ml. of 2-ethoxyethanol were refluxed 10 g. of 6-chloro-1-p-chlorophenyl-4-phenyl-2-pyridone and 5 g. of 1,3-propanediamine for 4 hours. Then, the reaction mixture was concentrated under reduced pressure and to the residue obtained were added 100 ml. of water and then concentrated hydrochloric acid to render strong acid, whereby crystals were precipitated. The crystals were recovered by filtration and after washing with water, 30 ml. of methanol was added to the crystals followed by heating to dissolve the crystals. Furthermore, 30 ml. of a 10% aqueous sodium carbonate solution was added to the solution followed by stirring sufficiently, 100 ml. of water was added to the solution, and then the product was extracted with 50 ml. of chloroform. The extract was dried over anhydrous sodium sulfate and concentrated under reduced pressure to provide crude crystals. By recrystallizing twice the crude crystals from acetonitrile, 3.2 g. of 6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine was obtained.

Melting point 201°-203° C.

Elemental analysis for C₁₄ H₁₄ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      74.21%     6.20%        12.49%                                     Calculated: 74.31%     6.24%        12.38%                                     ______________________________________                                    

EXAMPLE 3

In 5 ml. of 2-ethoxyethanol were refluxed 2 g. of 6-chloro-1-p-chlorophenyl-4-phenyl-2-pyridone and 1.2 g. of N-methyl-1,3-propanediamine for 50 hours. Then, by treating the reaction mixture as in Example 2, crude crystals were obtained. The crude crystals were applied to a silica gel column chromatography using 5 g. of silica gel and purified using a chloroform containing 1% methanol as an eluting solution. Furthermore, the crystals obtained were recrystallized from ethyl acetate to provide 0.42 g. of 1-methyl-6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 142°-143° C.

Elemental analysis for C₁₅ H₁₆ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      75.13%     6.79%        11.91%                                     Calculated: 74.97%     6.71%        11.66%                                     ______________________________________                                    

EXAMPLE 4

In 10 ml. of 2-ethoxyethanol were refluxed 5 g. of 6-chloro-1-p-chlorophenyl-4-phenyl-2-pyridone and 3 g. of N-ethylethylenediamine for 20 hours. Then, the reaction mixture was concentrated under reduced pressure and to the residue obtained were added 30 ml. of water and then concentrated hydrochloric acid to render strong acid, whereby crystals were precipitated. The crystals were recovered by filtration and after washing with water, 15 ml. of methanol was added to the crystals followed by heating to dissolve the crystals. Then, 15 ml. of a 10% aqueous sodium carbonate solution was added to the solution and after stirring sufficiently, 50 ml. of water was added to the mixture to precipitate crystals. The crude crystals thus formed were recovered by filtration and recrystallized twice from aqueous ethyl acetate to provide 2.0 g. of 1-ethyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]-pyridine dihydrate.

Melting point 83°-85° C.

Elemental analysis for C₁₅ H₂₀ N₂ O₃ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      65.01%     7.36%        9.95%                                      Calculated: 65.20%     7.29%        10.14%                                     ______________________________________                                    

EXAMPLE 5

In 10 ml. of 2-ethoxyethanol were refluxed 5 g. of 6-chloro-1-p-chlorophenyl-4-phenyl-2-pyridone and 2.1 g. of ethylenediamine for 5 hours. Then, the reaction mixture was concentrated under reduced pressure and after adding 30 ml. of water to the residue obtained, concentrated hydrochloric acid was added to render strong acid, whereby crystals were precipitated. The crystals were recovered by filtration and after washing with water, 30 ml. of methanol was added to the crystals followed by heating to dissolve the crystals. Thereafter, 30 ml. of a 5% aqueous potassium carbonate solution was added to the solution followed by stirring sufficiently and then the reaction mixture was cooled. The crystals thus precipitated were recovered by filtration and recrystallized from acetonitrile to provide 1.5 g. of 5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 198°-200° C.

Elemental analysis for C₁₃ H₁₂ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      73.72%     5.80%        13.53%                                     Calculated: 73.57%     5.70%        13.20%                                     ______________________________________                                    

EXAMPLE 6

In 3 ml. of 2-ethoxyethanol were refluxed 1.05 g. of 6-bromo-1-(4-methylphenyl)-4-phenyl-2-pyridone and 0.4 g. of ethylenediamine for 5 hours. Then, by treating the reaction mixture as in Example 5, 0.35 g. of 5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine was obtained.

Melting point 198°-200° C.

EXAMPLE 7

In 3 ml. of 2-ethoxyethanol were refluxed 1.05 g. of 6-bromo-4-(2-chlorophenyl)-1-phenyl-2-pyridone and 0.6 g. of N-ethylethylenediamine for 27 hours. Then, by treating the reaction mixture as in Example 4, crude crystals were obtained. The crude crystals were recovered by filtration and recrystallized from ethyl acetate to provide 0.23 g. of 1-ethyl-7-(2-chlorophenyl)-5-oxo-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 150°-152° C.

Elemental analysis for C₁₅ H₁₅ ClN₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      65.30%     5.74%        9.87%                                      Calculated: 65.57%     5.50%        10.20%                                     ______________________________________                                    

EXAMPLE 8

A mixture of 1.05 g. of 6-bromo-4-(2-chlorophenyl)-1-phenyl-2-pyridone, 0.6 g. of 1,3-propanediamine, and 3 ml. of 2-ethoxyethanol was refluxed for 4 hours. The reaction mixture obtained was concentrated and then to the residue formed were added 10 ml. of ethyl acetate and 20 ml. of a 10% aqueous hydrochloric acid solution followed by stirring sufficiently. Thereafter, the aqueous layer formed was separated, alkalified by the addition of sodium carbonate, and then extracted with 20 ml. of ethyl acetate. The ethyl acetate extract was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue obtained was applied to a column chromatography using 10 g. of silica gel and purified using chloroform as an eluting solution. The crystals obtained were recrystallized from acetonitrile to provide 0.2 g. of 8-(2-chlorophenyl)-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 194°-195° C.

Elemental analysis for C₁₄ H₁₃ N₂ OCl:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      64.35%     4.93%        10.57%                                     Calculated: 64.50%     5.03%        10.74%                                     ______________________________________                                    

EXAMPLE 9

A mixture of 2 g. of 6-chloro-1-(4-chlorophenyl)-4-phenyl-2-pyridone, 2 g. of N-benzylethylenediamine, and 5 ml. of 2-ethoxyethanol was refluxed for 50 hours. Then, by treating the reaction mixture obtained as in Example 5, 0.5 g. of 1-benzyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine was obtained.

Melting point 165°-167° C.

Elemental analysis for C₂₀ H₁₈ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      79.46%     6.14%        9.36%                                      Calculated: 79.44%     6.00%        9.26%                                      ______________________________________                                    

EXAMPLE 10

A mixture of 2 g. of 6-chloro-1-(4-chlorophenyl)-4-phenyl-2-pyridone, 2 g. of N-cyclohexylethylenediamine, and 5 ml. of 2-ethoxyethanol was refluxed for 100 hours. The reaction mixture obtained was concentrated under reduced pressure and the residue formed was applied to a column chromatography using 30 g. of silica gel and purified using chloroform as an eluting solution. Thereafter, diluted hydrochloric acid was added to 1 g. of the oily product obtained to crystallize the product. The crystals formed were recovered and recrystallized from a mixture of acetonitrile and ethyl acetate to provide 0.5 g. of 1-cyclohexyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine hydrochloride.

Melting point 210°-214° C.

Elemental analysis for C₁₉ H₂₃ N₂ OCl:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      69.51%     7.20%        8.42%                                      Calculated: 68.98%     7.01%        8.47%                                      ______________________________________                                    

EXAMPLE 11

A mixture of 1 g. of 6-chloro-1-(4-chlorophenyl)-4-phenyl-2-pyridone, 0.7 g. of N-isopropylethylenediamine, and 2.5 ml. of 2-ethoxyethanol was refluxed for 100 hours. The reaction mixture obtained was concentrated under reduced pressure and 10 ml. of water was added to the residue thus formed. Then, the mixture was strongly acidified by the addition of concentrated hydrochloric acid to precipitate crystals. The crystals were recovered by filtration, dissolved in 10 ml. of methanol under heating, and 10 ml. of a 10% aqueous potassium carbonate solution was added to the solution followed by stirring sufficiently. Furthermore, after adding 40 ml. of water, the mixture was extracted with 20 ml. of chloroform. The chloroform extract was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue formed was applied to a column chromatography using 5 g. of silica gel and purified using chloroform as an eluting solution. Thereafter, water was added to the oily product obtained to crystallize the product and the crystals formed were recovered and recrystallized from ether to provide 0.3 g. of 1-isopropyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine di-hydrate.

Melting point 74°-78° C.

EXAMPLE 12

In 15 ml. of ethylene glycol were heated 10.2 g. of 6-chloro-1-p-chlorophenyl-4-phenyl-2-pyridone and 4.6 g. of 2-aminoethanethiol to 200° C. for 5 hours. After the reaction was over, the reaction mixture was mixed with 100 ml. of ethyl acetate, washed three times each time with 30 ml. of 1 normal hydrochloric acid and then thrice each with 30 ml. of water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. Then, 7.0 g. of the crude crystals obtained was applied to a silica gel column chromatography using 150 g. of silica gel and purified using a chloroform containing 1% methanol as an eluting solution. The crystals obtained were further recrystallized from ethyl acetate to provide 3.5 g. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine.

Melting point 132°-134° C.

Elemental analysis for C₁₃ H₁₁ NOS:

    ______________________________________                                                 C       H         N         S                                          ______________________________________                                         Found:    68.12%    4.84%     6.13%   13.61%                                   Calculated:                                                                              68.10%    4.84%     6.11%   13.98%                                   ______________________________________                                    

EXAMPLE 13

A mixture of 0.8 g. of 6-chloro-3-phenyl-2-pyridone, 0.7 g. of N-methylethylenediamine, and 2 ml. of o-dichlorobenzene was refluxed for 5 hours. After the reaction was over, the reaction mixture was cooled and after adding thereto 10 ml. of chloroform, the mixture was washed with 5 ml. of diluted hydrochloric acid and 5 ml. of water. The chloroform layer was concentrated under reduced pressure and the residue obtained was, under shading, applied to a column chromatography using 10 g. of silica gel and purified using a chloroform containing 2% methanol as an eluting solution. The crystals obtained were recrystallized from xylene to provide 0.23 g. of 1-methyl-5-oxo-6-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 128°-130° C.

Elemental analysis for C₁₄ H₁₄ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.31%     6.24%        12.38%                                     Found:      74.00%     6.55%        12.02%                                     ______________________________________                                    

EXAMPLE 14

In 5 ml. of 2-ethoxyethanol were refluxed 2 g. of 6-chloro-1-(4-chlorophenyl)-4-phenyl-2-pyridone and 1.4 g. of N-(2'-hydroxyethyl)ethylenediamine for 15 hours. The reaction mixture obtained was concentrated and 10 ml. of water was added to the residue formed. Then, the pH of the mixture was adjusted to about 1 by adding concentrated hydrochloric acid to precipitate crystals, which were recovered by filtration. The crystals were recrystallized from 100 ml. of water to provide crude hydrochloride salt. The hydrochloride salt was mixed with 50 ml. of water and the mixture was alkalified by adding thereto sodium carbonate with stirring under heating. After cooling the mixture, the product was extracted twice each time with 10 ml. of chloroform. The extracts were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crystalline residue obtained was recrystallized from aqueous ethyl acetate containing activated carbon to provide 0.9 g. of 1-(2-hydroxyethyl)-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine

Melting point 159°-161° C.

Elemental analysis for C₁₅ H₁₆ N₂ O₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 70.29%     6.29%        10.93%                                     Found:      69.80%     6.25%        11.25%                                     ______________________________________                                    

EXAMPLE 15

A mixture of 2.1 g. of 6-chloro-1-(4'-chlorophenyl)4-phenyl-2-pyridone, 1.2 g. of 1,4-diaminobutane, and 6 ml. of 2-ethoxyethanol was refluxed for 40 hours. The reaction mixture obtained was concentrated under reduced pressure and the residue formed was dissolved in 20 ml. of chloroform followed by washing with 10 ml. of water. The mixture was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution to provide 0.6 g. of oily 7-oxo-9-phenyl-1,2,3,4,5,7-hexahydropyrido [1,2-a][1,3]diazepine.

Mass spectrum m/e: 240 (M⁺) Nuclear magnetic resonance spectra (CHCl₃): δ(ppm): 1.73 (4H, m), 3.15 (2H, m), 4,32 (2H, m), 4.97 (1H, broad S), 5,93 (1H, d), 6.32 (1H, d), 7.1-7.7 (5H, m)

EXAMPLE 16

In 10 ml. of o-dichlorobenzene were dissolved 3.16 g. of 6-chloro-1-(4-chlorophenyl)-4-phenyl-2-pyridone and 1.6 g. of 1,2-diaminopropane and the solution was heated to 150°-160° C. for 20 hours using an air-cooling tube. The reaction mixture obtained was concentrated under reduced pressure and the residue obtained was mixed with water and acidified with hydrochloric acid to precipitate crystals, which were recovered by filtration. The solid product thus obtained was dissolved in methanol and after alkalifying the solution with an aqueous potassium carbonate solution, the product was extracted three times each time with 10 ml. of ethyl acetate. The extracts were combined and the solvent was distilled off under reduced pressure. The residue obtained was applied to a silica gel column chromatography and purified using a mixture of ethyl acetate and methanol as an eluting agent. The eluates containing the desired compound were collected and the solvent was distilled off. The crude crystals obtained were recrystallized from a mixture of ethyl acetate and acetonitrile to provide 1 g. of 3-methyl-5 -oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 170°-172° C.

Elemental analysis for C₁₄ H₁₄ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.31%     6.24%        12.38%                                     Found:      74.12%     6.23%        12.17%                                     ______________________________________                                    

EXAMPLE 17

In 10 ml. of ethanol was dissolved 280 mg. of sodium and then 1.5 g. of 2-aminopropanethiol hydrochloride was dissolved in the solution. The solution thus obtained was allowed to stand for 15 minutes at room temperature and then ethanol was distilled off under reduced pressure. The residue formed was dissolved in 10 ml. of ethylene glycol and then after adding to the solution 3.16 g. of 6-chloro-1-(4-chlorophenyl)4-phenyl-2-pyridone, the mixture was heated to 190°-200° C. for 5 hours using an air-cooling tube. Then, the solvent was distilled off under reduced pressure from the reaction mixture and the residue obtained was extracted three times each time with 20 ml. of ethyl acetate. The extracts were combined, washed successively with 1 normal hydrochloric acid, an aqueous sodium carbonate solution, and then water, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure and the residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The eluates containing the desired compound were collected and the solvent was distilled off to provide crude crystals. The crude crystals were recrystallized from a mixture of cyclohexane and ethyl acetate to provide 1.5 g. of 3-methyl-5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine.

Melting point 117°-118° C.

Elemental analysis for C₁₄ H₁₃ NOS:

    ______________________________________                                                 C       H         N         S                                          ______________________________________                                         Calculated:                                                                              69.11%    5.39%     5.76%   13.18%                                   Found:    69.16%    5.50%     6.08%   13.04%                                   ______________________________________                                    

EXAMPLE 18-40

The physical constants for Examples 18 through 40 are tabulated in Table 5. The compounds were prepared according to the procedures described in Examples 1 through 17.

                                      TABLE 5                                      __________________________________________________________________________      ##STR70##                                                                     Example                                                                             R.sub.1 R.sub.2   R.sub.3     X         Y       mp(°C.)            __________________________________________________________________________     18   H                                                                                       ##STR71##                                                                               H                                                                                           ##STR72##                                                                               (CH.sub.2).sub.2                                                                        74-78 (di-hydrate)       19   H                                                                                       ##STR73##                                                                               H                                                                                           ##STR74##                                                                               (CH.sub.2).sub.2                                                                       215-218                   20   H                                                                                       ##STR75##                                                                               H                                                                                           ##STR76##                                                                               (CH.sub.2).sub.3                                                                       200-202                   21   H                                                                                       ##STR77##                                                                               H                                                                                           ##STR78##                                                                               (CH.sub.2).sub.3                                                                       138-140  (mono-hydrat                                                          e)                        22   H       CH.sub.3  H                                                                                           ##STR79##                                                                               (CH.sub.2).sub.2                                                                       144-146                   23   H       CH.sub.3  H                                                                                           ##STR80##                                                                               (CH.sub.2).sub.2                                                                       168-169                   24   H       CH.sub.3  H                                                                                           ##STR81##                                                                               (CH.sub.2).sub.3                                                                       100-101                   25   H                                                                                       ##STR82##                                                                               H                                                                                           ##STR83##                                                                               (CH.sub.2).sub.3                                                                        77-78                    26   H                                                                                       ##STR84##                                                                               H                                                                                           ##STR85##                                                                               (CH.sub.2).sub.2                                                                       112-114                   27   (CH.sub.2).sub.3  H                                                                                           ##STR86##                                                                               (CH.sub.2).sub.2                                                                       162-163                   28   (CH.sub.2).sub.3  H                                                                                           ##STR87##                                                                               (CH.sub.2).sub.3                                                                        71-72                    29   (CH.sub.2).sub. 4 H                                                                                           ##STR88##                                                                               (CH.sub.2).sub.2                                                                       111-112                   30   (CH.sub.2).sub.4  H                                                                                           ##STR89##                                                                               (CH.sub.2).sub.3                                                                       108-109                   31                                                                                   ##STR90##                                                                             CH.sub.3  H                                                                                           ##STR91##                                                                               (CH.sub.2).sub.2                                                                       215-216                   32                                                                                   ##STR92##                                                                             CH.sub.3  H                                                                                           ##STR93##                                                                               (CH.sub.2).sub.3                                                                       159-160                   33   CH.sub.3                                                                                ##STR94##                                                                               H                                                                                           ##STR95##                                                                               (CH.sub.2).sub.2                                                                       135-136                   34   CH.sub.3                                                                                ##STR96##                                                                               H                                                                                           ##STR97##                                                                               (CH.sub.2).sub.3                                                                       114-115 (hydrochlorid                                                          e)                        35   H                                                                                       ##STR98##                                                                               H                                                                                           ##STR99##                                                                                ##STR100##                                                                            145-146                   36   CH.sub.3                                                                               CH.sub.3  CH.sub.3                                                                                    ##STR101##                                                                              (CH.sub.2).sub.2                                                                       278                       37                                                                                   ##STR102##                                                                            CH.sub.3                                                                                  ##STR103##                                                                                 ##STR104##                                                                              (CH.sub.2).sub.2                                                                       239-240                   38                                                                                   ##STR105##                                                                            CH.sub.3                                                                                  ##STR106##                                                                                 ##STR107##                                                                              (CH.sub.2).sub.2                                                                       121-122                   39   H       CH.sub.3                                                                                  ##STR108##                                                                                 ##STR109##                                                                              (CH.sub.2).sub.3                                                                       205-206                   40   H                                                                                       ##STR110##                                                                               ##STR111##                                                                                 ##STR112##                                                                              (CH.sub.2).sub.3                                                                       217-218                   __________________________________________________________________________

EXAMPLE 41

In 5 ml. of diglyme were refluxed 3 g. of ethyl 3-(cyanomethylene)butyrate and 1.9 g. of N-methylethylenediamine for 12 hours. The solvent was distilled off from the reaction mixture under reduced pressure and the residue formed was applied to a silica gel column chromatography and purified using a mixture of chloroform and methanol (volume ratio 49:1) as an eluting solution. The crystals formed were recrystallized from a mixture of n-hexane and ethyl acetate (volume ratio 1:1) to provide 1 g. of 1,7-dimethyl-5-oxo-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 144°-146° C.

Elemental analysis for C₉ H₁₂ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 65.83%     7.37%        17.06%                                     Found:      65.54%     7.39%        17.14%                                     ______________________________________                                    

EXAMPLE 42

In 5 ml. of diglyme were refluxed 3 g. of ethyl 3-(cyanomethylene)butyrate and 1.6 g. of trimethylenediamine for 12 hours under heating. The reaction mixture was poured into 30 ml. of ice water and precipitated by-products was filtered off.

The filtrate was extracted three times each time with 30 ml. of chloroform and the extracts were combined and the solvent was distilled off under reduced pressure.

The liquid residue obtained was applied to a silica gel column chromatography and purified using a mixture of chloroform and methanol (volume ratio 19:1) as a eluting solution. Then, the crystals obtained were recrystallized from a mixture of cyclohexane and ethyl acetate (volume ratio 1:1) to provide 0.5 g. of 8-methyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 168°-169° C.

Elemental analysis for C₉ H₁₂ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 65.83%     7.37%        17.06%                                     Found:      65.92%     7.21%        17.25%                                     ______________________________________                                    

EXAMPLE 43

In 5 ml. of diglyme were refluxed 3 g. of methyl 3-(cyanomethylene)butyrate and 1.9 g. of N-methyltrimethylenediamine for 12 hours. After the reaction was over, the solvent was distilled off from the reaction mixture under reduced pressure and the liquid residue formed was applied to a silica gel column chromatography and purified using a mixture of chloroform and methanol (volume ratio 19:1) as a eluting solution. The crystals formed were recrystallized from a mixture of cyclohexane and ethyl acetate (volume ratio 1:1) to provide 1 g. of 1,8-dimethyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 100°-101° C.

Elemental analysis for C₁₀ H₁₄ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 67.39%     7.92%        15.72%                                     Found:      67.12%     8.07%        15.65%                                     ______________________________________                                    

EXAMPLE 44

In 5 ml. of o-dichlorobenzene were dissolved 2 g. of ethyl 3-cyanomethylene-5-methylhexanoate and 1.1 g. of N-methyltrimethylenediamine and the solution was heated to 170°-180° C. for 24 hours using an air-cooling tube.

The reaction mixture was mixed with 20 ml. of benzene and extracted thrice each with 30 ml. of 1 normal hydrochloric acid. The hydrochloric acid extracts were combined, alkalified with sodium carbonate, and extracted thrice each with 30 ml. of ethyl acetate. The ethyl acetate extracts were combined, washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure.

The residue formed was recrystallized from cyclohexane to provide 250 mg. of 8-isobutyl-1-methyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 77°-78° C.

Elemental analysis for C₁₃ H₂₀ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 70.87%     9.15%        12.72%                                     Found:      70.71%     9.47%        12.89%                                     ______________________________________                                    

EXAMPLE 45

In 5 ml. of o-dichlorobenzene were dissolved 2 g. of ethyl 3-cyanomethylene-5-methylhexanoate and 0.9 g. of N-methylethylenediamine and the solution was heated to 170°-180° C. for 24 hours using an air-cooling tube. The reaction mixture was mixed with 20 ml. of benzene and extracted three times each time with 30 ml. of 1 normal hydrochloric acid. The hydrochloric acid extracts were combined, alkalified with sodium carbonate, and extracted thrice each with 30 ml. of chloroform. The chloroform extracts were combined, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The residue formed was recrytstallized from cyclohexane to provide 700 mg. of 7-isobutyl-1-methyl-5-oxo-1,2,3,5-tetrahydro-imidazo[1,2-a]pyridine.

Melting point 112°-114° C.

Elemental analysis for C₁₂ H₁₈ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 69.87%     8.80%        13.58%                                     Found:      69.72%     8.66%        13.70%                                     ______________________________________                                    

EXAMPLE 46

In 10 ml. of o-dichlorobenzene were dissolved 4.3 g. of ethyl 4-cyano-3-phenyl-3-butenoate and 1.8 g. of 2-aminoethanethiol and the solution was refluxed for 2 hours. After the reaction was over, the reaction mixture was applied to a silica gel column chromatography using 60 g. of silica gel and purified using a chloroform containing 1% ethanol as an eluting solution. The crude crystals obtained were recrystallized from ethanol to provide 0.4 g. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine.

Melting point 132°-134° C.

Elemental analysis for C₁₃ H₁₁ NSO:

    ______________________________________                                                 C       H         N         S                                          ______________________________________                                         Calculated:                                                                              68.10%    4.84%     6.11%   13.98%                                   Found:    68.23%    4.87%     6.08%   13.71%                                   ______________________________________                                    

EXAMPLE 47

In 2 ml. of ethylene glycol were heated 0.6 g. of 3-(4-methoxyphenyl)-2-pentenedioic acid and 0.15 g. of ethylenediamine to 160°-170° C. for one hour. After cooling, the reaction mixture was mixed with 20 ml. of water and the crystals precipitated were recovered by filtration and recrystallized from aqueous methanol to provide 0.12 g. of 7-(4-methoxyphenyl)-5-oxo-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 215°-218° C.

Elemental analysis for C₁₄ H₁₄ N₂ O₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 69.41%     5.82%        11.56%                                     Found:      69.21%     5.96%        11.42%                                     ______________________________________                                    

EXAMPLE 48

In 5 ml. of dichlorobenzene were refluxed 3 g. of ethyl 4-cyano-3-(4-chlorophenyl)-3-butenoate and 1.2 g. of N-methyl-1,3-propanediamine for 20 hours. The reaction mixture was concentrated under reduced pressure and the crystalline residue formed was washed with 20 ml. of ethyl acetate and recrystallized from methanol to provide 1.5 g. of 8-(4-chlorophenyl)-1-methyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 200°-202° C.

Elemental analysis for C₁₅ H₁₅ N₂ OCl:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 65.57%     5.50%        10.20%                                     Found:      65.54%     5.34%         9.88%                                     ______________________________________                                    

EXAMPLE 49

In 5 ml. of dichlorobenzene were refluxed 3 g. of ethyl 4-cyano-3-(4-methoxyphenyl)-3-butenoate and 1.2 g. of N-methyl-1,3-propanediamine for 20 hours. The reaction mixture was concentrated under reduced pressure and the crystalline residue formed was recrystallized twice from aqueous methanol to provide 1.1 g. of 8-(4-methoxyphenyl)-1-methyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine mono-hydrate.

Melting point 138°-140° C.

Elemental analysis for C₁₆ H₂₀ N₂ O₃ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 66.65%     6.99%        9.72%                                      Found:      67.05%     7.05%        9.77%                                      ______________________________________                                    

EXAMPLE 50

A solution of 3.6 g. of a mixture of 2-cyanomethylenecyclopentane-1-carboxylic acid ethyl ester and 2-cyanomethyl-1-cyclopentene-1-carboxylic acid ethyl ester and 1.8 g. of N-methylethylenediamine in 10 ml. of o-dichlorobenzene was heated to 170°-180° C. for 24 hours with stirring using an air-cooling tube. Then, the solvent was distilled off from the reaction mixture under reduced pressure. The residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The crystals obtained were recrystallized from ethyl acetate to provide 1.0 g. of 1-methyl-5-oxo-1,2,3,6,7,8-hexahydroimidazo[1,2-b]1H-2-pyrindine.

Melting point 162°-163° C.

Elemental analysis for C₁₁ H₁₄ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      69.15%     7.16%        14.63%                                     Calculated: 69.45%     7.42%        14.72%                                     ______________________________________                                    

EXAMPLE 51

To 10 ml. of o-dichlorobenzene containing 2.3 g. of N-methyl-1,3-diaminopropane was added 3.6 g. of a mixture of 2-cyanomethylenecyclopentane-1-carboxylic acid ethyl ester and 2-cyanomethyl-1-cyclopentene-1-carboxylic acid ethyl ester and the mixture was heated to 170°-180° C. for 24 hours with stirring using an air-cooling tube. Then, the solvent was distilled off from the reaction mixture under reduced pressure and the residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The crystals obtained were recrystallized from a mixture of ethyl acetate and n-hexane to provide 3 g. of 1-methyl-6-oxo-1,2,3,4,7,8,9-heptahydropyrimido[1,2-b]1H-2-pyrindine.

Melting point 71°-72° C.

Elemental analysis for C₁₂ H₁₆ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      70.23%     7.96%        13.90%                                     Calculated: 70.56%     7.90%        13.71%                                     ______________________________________                                    

EXAMPLE 52

In 5 ml. of o-dichlorobenzene was dissolved 2 g. of a mixture of 2-cyanomethylene-cyclohexane-1-carboxylic acid ethyl ester and 2-cyanomethyl-1-cyclohexene-1-carboxylic acid ethyl ester (1:1) and 900 mg. of N-methylethylenediamine and the solution was heated to 170°-180° C. for 12 hours using an air-cooling tube. The reaction mixture was mixed with 20 ml. of benzene and extracted three times each time with 20 ml. of 1 normal hydrochloric acid. The hydrochloric acid extracts were combined, alkalified with sodium carbonate, and extracted thrice each with 20 ml. of ethyl acetate. The ethyl acetate extracts were combined, washed with water, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure and the solid residue formed was recrystallized from cyclohexane to provide 120 mg. of 1-methyl-5-oxo-1,2,3,5,6,7,8,9-octahydroimidazo[1,2-b]isoquinoline.

Also, the benzene solution was combined with the filtrate in the recrystallization and the solution obtained was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. Then, the crystals obtained were recrystallized from cyclohexane to provide 150 mg. of 1-methyl-5-oxo-1,2,3,5,6,7,8,9-octahydroimidazo[1,2-b]isoquinoline.

Melting point 111°-112° C.

Elemental analysis for C₁₂ H₁₆ ON₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 70.56%     7.96%        13.71%                                     Found:      70.84%     8.13%        13.55%                                     ______________________________________                                    

EXAMPLE 53

In 5 ml. of o-dichlorobenzene were dissolved 4 g. of a mixture of 2-cyanomethylene-cyclohexane-1-carboxylic acid ethyl ester and 2-cyanomethyl-1-cyclohexane-1-carboxylic acid ethyl ester (1:1) and 2.3 g. of N-methyl-1,3-diaminopropane and the solution was heated to 170°-180° C. for 24 hours using an air-cooling tube. From the reaction mixture, the solvent was distilled off under reduced pressure and the oily residue obtained was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The crystals thus obtained was recrystallized from a mixture of ethyl acetate and n-hexane to provide 800 mg. of 1-methyl-6-oxo-1,2,3,4,6,7,8,9,10-nonahydropyrimido[1,2-b]isoquinoline.

Melting point 108°-109° C.

Elemental analysis for C₁₃ H₁₈ ON₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 71.53%     8.31%        12.83%                                     Found:      71.38%     8.55%        12.50%                                     ______________________________________                                    

EXAMPLE 54

In 10 ml. of o-dichlorobenzene were dissolved 4.6 g. of ethyl 4-cyano-3-methyl-2-phenyl-3-butenoate and 1.8 g. of N-methylethylenediamine and the solution was heated to 170°-180° C. for 30 hours using an air-cooling tube. Then, the reaction mixture was cooled, whereby crystals were precipitated and after adding thereto 50 ml. of ether, the crystals were recovered by filtration.

The crystals thus obtained were recrystallized from a mixture of ethyl acetate and acetonitrile to provide 2 g. of 1,7-dimethyl-5-oxo-6-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 215°-216° C.

Elemental analysis for C₁₅ H₁₆ ON₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.97%     6.71%        11.66%                                     Found:      74.78%     6.64%        11.66%                                     ______________________________________                                    

In addition, ethyl 4-cyano-3-methyl-2-phenyl-3-butenoate used as the raw material in this example was prepared by the following manner.

In 90 ml. of benzene were dissolved 62 g. of ethyl α-phenyl-acetoacetate, 27 g. of cyanoacetic acid, 5 g. of ammonium acetate, and 9 ml. of acetic acid and the solution was refluxed using a dehydrating means to provide 44 g. of ethyl 4-cyano-3-methyl-2-phenyl-3-butenoate.

Boiling point 107°-116° C./0.1 mm.Hg

(purity about 87%).

EXAMPLE 55

In 10 ml. of o-dichlorobenzene were dissolved 4.6 g. of ethyl 4-cyano-3-methyl-2-phenyl-3-butenoate and 2.1 g. of N-methyl-1,3-diaminopropane and the solution was heated to 170°-180° C. for 20 hours using an air-cooling tube. The reaction mixture was mixed with 20 ml. of benzene and extracted thrice each with 30 ml. of a 1 normal hydrochloric acid. The hydrochloric acid extracts were combined and alkalified with sodium carbonate, whereby crystals were precipitated. The crystals were then recovered by filtration and recrystallized from xylene to provide 800 mg. of 1,8-dimethyl-6-oxo-7-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Furthermore, the benzene solution was concentrated under reduced pressure and the residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The solid product obtained was recrystallized from xylene to provide 450 mg. of 1,8-dimethyl-6-oxo-7-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine.

Melting point 159°-160° C.

Elemental analysis for C₁₆ H₁₈ ON₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 75.56%     7.13%        11.01%                                     Found:      75.47%     7.12%        10.96%                                     ______________________________________                                    

EXAMPLE 56

In 10 ml. of o-dichlorobenzene were dissolved 4.6 g. of ethyl 4-cyano-2-methyl-3-phenyl-3-butanoate and 1.8 g. of N-methylethylenediamine and the solution was heated to 170°-180° C. for 24 hours using an air-cooling tube. Then, the solvent was distilled off from the reaction mixture under reduced pressure and the oily residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The solid product obtained was recrystallized from ethyl acetate to provide 1.1 g. of 1,6-dimethyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 135°-136° C.

Elemental analysis for C₁₅ H₁₆ ON₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.97%     6.71%        11.66%                                     Found:      75.10%     6.75%        11.57%                                     ______________________________________                                    

In addition, ethyl 4-cyano-2-methyl-3-phenyl-3-butenoate used as the raw material in this example was prepared by the following manner.

In 130 ml. of benzene were dissolved 90 g. of ethyl α-benzoylpropionate, 39 g. of cyanoacetic acid, 7.3 g. of ammonium acetate, and 13 ml. of acetic acid and the solution was refluxed using a dehydrating means to provide 35 g. of ethyl 4-cyano-2-methyl-3-phenyl-3-butenoate.

Boiling point 101°-115° C./0.1 mm.Hg

(purity about 80%).

EXAMPLE 57

In 10 ml. of o-dichlorobenzene were dissolved 4.69 g. of ethyl 4-cyano-2-methyl-3-phenyl-3-butenoate and 2.1 g. of N-methyl-1,3-diaminopropane and the solution was heated to 170°-180° C. for 24 hours using an air-cooling tube.

The reaction mixture was mixed with 30 ml. of benzene, washed twice each time with 20 ml. of water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure to provide 3.9 g. of a oily residue. The residue was applied to a silica gel chromatography and purified using chloroform as an eluting solution, whereby 3 g. of oily 1,7-dimethyl-6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine was obtained.

In 100 ml. of ethyl ether was dissolved 3 g. of the oily product and then 14 ml. of methanol containing 10% hydrogen chloride was added to it while stirring under ice cooling. The crystals precipitated were recovered by filtration and recrystallized from a mixture of ethyl acetate and acetonitrile to provide 1.7 g. of 1,7-dimethyl-6oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine hydrochloride.

Mleting point 114°-115° C.

Elemental analysis for C₁₆ H₁₉ ON₂ Cl:

    ______________________________________                                                 C       H         N         Cl                                         ______________________________________                                         Calculated:                                                                              66.09%    6.59%     9.63%   12.19%                                   Found:    66.23%    6.62%     9.74%   12.22%                                   ______________________________________                                    

EXAMPLE 58

A solution of 20 g. of ethyl 4-cyano-3-phenyl-3-butenoate and 10 g. of N-methyl-1,3-diaminopropane in 15 ml. of o-dichlorobenzene was heated to 120° C. for 2 hours and then after removing low-boiling components by distillation, the inside temperature of the system was raised to 170° C. and maintained at the same temperature for 5 hours. Then, the solution was cooled and the crystals formed were recovered by filtration, washed with 20 ml. of ethyl acetate and recrystallized from ethyl acetate to provide 9.8 g. of 1-methyl-6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine. Mleting point 143°-144° C.

EXAMPLE 59

By following the same procedure as in Example 58 using 20 g. of ethyl 4-cyano-3-phenyl-3-butenoate, 16 g. of ethylenediamine, and 15 ml. of o-dichlorobenzene, crude crystals were obtained and recrystallized from isopropanol to provide 10.5 g. of 5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 200°-202° C.

EXAMPLE 60-76

The physical constants for Examples 60 through 76 are tabulated in Table 6. The compounds were prepared according to the procedures described in Examples 41 through 59.

                                      TABLE 6                                      __________________________________________________________________________      ##STR113##                                                                    Example                                                                              R.sub.1  R.sub.2                                                                              R.sub.3     X          Y       mp(°C.)             __________________________________________________________________________     60    H                                                                                        ##STR114##                                                                          H                                                                                           ##STR115##                                                                               (CH.sub.2).sub.2                                                                       159                        61    H                                                                                        ##STR116##                                                                          H                                                                                           ##STR117##                                                                               (CH.sub.2).sub.3                                                                       201-203                    62    H                                                                                        ##STR118##                                                                          H                                                                                           ##STR119##                                                                               (CH.sub.2).sub.2                                                                        83-85 (di-hydrate)        63    H                                                                                        ##STR120##                                                                          H                                                                                           ##STR121##                                                                               (CH.sub.2).sub.2                                                                       150-152                    64    H                                                                                        ##STR122##                                                                          H                                                                                           ##STR123##                                                                               (CH.sub.2).sub.3                                                                       194-195                    65    H                                                                                        ##STR124##                                                                          H                                                                                           ##STR125##                                                                               (CH.sub.2).sub.3                                                                       165-167                    66    H                                                                                        ##STR126##                                                                          H                                                                                           ##STR127##                                                                               (CH.sub.2).sub.2                                                                       210-214 (hydrochloride                                                         )                          67                                                                                    ##STR128##                                                                             H     H                                                                                           ##STR129##                                                                               (CH.sub.2).sub.2                                                                       128-130                    68    H                                                                                        ##STR130##                                                                          H                                                                                           ##STR131##                                                                                ##STR132##                                                                            170-172                    69    H                                                                                        ##STR133##                                                                          H                                                                                           ##STR134##                                                                                ##STR135##                                                                            145-146                    70    CH.sub.3 CH.sub.3                                                                             CH.sub.3                                                                                    ##STR136##                                                                               (CH.sub.2).sub.2                                                                       278                        71                                                                                    ##STR137##                                                                             CH.sub.3                                                                              ##STR138##                                                                                 ##STR139##                                                                               (CH.sub.2).sub.2                                                                       239-240                    72                                                                                    ##STR140##                                                                             CH.sub.3                                                                              ##STR141##                                                                                 ##STR142##                                                                               (CH.sub.2).sub.2                                                                       121-122                    73    H        CH.sub.3                                                                              ##STR143##                                                                                 ##STR144##                                                                               (CH.sub.2).sub.2                                                                       156-158                    74    H        CH.sub.3                                                                              ##STR145##                                                                                 ##STR146##                                                                               (CH.sub.2).sub.3                                                                       205-206                    75    H                                                                                        ##STR147##                                                                          H                                                                                           ##STR148##                                                                               (CH.sub.2).sub.4                                                                       oily product(*)            76    H                                                                                        ##STR149##                                                                           ##STR150##                                                                                 ##STR151##                                                                               (CH.sub.2).sub.3                                                                       217-218                    __________________________________________________________________________      (*):                                                                           Mass spectrum m/e: 240 (M.sup.+).                                              Nuclear magnetic resonance spectra (CHCl.sub.3):                               δ(ppm): 1.73 (4H, m), 3.15 (2H, m), 4.32 (2H, m) 4.97 (1H, broad S)      5.93 (1H, d), 6.32 (1H, d), 7.1-7.7 (5H, m)                              

EXAMPLE 77

To 20 ml. of methanol containing 0.3 g. of metallic sodium was added 1 g. of 6-chloro-1-(2-hydroxyethyl)-4-phenyl-2-pyridone and the mixture was refluxed for 4 hours. After the reaction was over, the reaction mixture was cooled, the solvent was distilled off, and after neutralizing with 1 normal hydrochloric acid, the reaction product was extracted twice each time with 50 ml. of ethyl acetate. The extracts were combined, dried and then the solvent was distilled off.

Thereafter, the residue formed was applied to a silica gel column chromatography and then the desired compound was separated using a mixture of chloroform and methanol as an eluting solution. The crude crystals thus obtained were recrystallized from a mixture of methanol and benzene to provide 290 mg. of 5-oxo-7-phenyl-2,3-dihydro-5H-oxazolo[3,2-a]pyridine,

Melting point 200°-203° C.

Elemental analysis for C₁₃ H₁₁ NO₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 73.23%     5.20%        6.57%                                      Found:      73.45%     5.25%        6.30%                                      ______________________________________                                    

EXAMPLE 78

(a). In 10 ml. of dry benzene was dispersed 720 mg. of 50% oily sodium hydride and while refluxing the suspension under heating, a solution of 3 g. of 6-chloro-4-phenyl-2-pyridone in a mixture of 20 ml. of benzene and 2 ml. of dimethylformamide was added dropwise to the suspension and thereafter, the mixture was further refluxed for 3 hours under heating. Then, after adding dropwise a solution of 2.2 g. of 3-bromopropanol in 10 ml. of benzene to the mixture, the resultant mixture was further refluxed overnight under heating. Thereafter, the reaction mixture was cooled and then extracted twice each with 50 ml. of ethyl acetate. The extracts were combined, washed with hydrochloric acid and then water, and dried. The solvent was then destilled off under reduced pressure from the reaction mixture and the residue formed was applied to a silica gel column chromatography and purified using a mixture of ethyl acetate and chloroform (volume ratio 1:1) as an eluting solution to provide 1.3 g, of purified 6-chloro-(3-hydroxypropyl)-4-phenyl-2-pyridone.

(b). Then, 1 g. of the purified 6-chloro-1-(3-hydroxypropyl)-4-phenyl-2-pyridone was added to 15 ml. of methanol containing a slightly excessive amount of sodium methoxide and the mixture was refluxed for 1.5 hours. After the reaction was over, the reaction mixture was cooled and filtered. The solvent was distilled off from the filtrate and the residue obtained was successively washed with diluted hydrochloric acid, water, and then ethyl acetate and then recrystallized from a mixture of benzene and hexane to provide 350 mg. of 6-oxo-8-phenyl-3,4-dihydro-2H,6H-pyrido[2,1-b][1,3]oxazine.

Melting point 134°-135° C.

Elemental analysis for C₁₄ H₁₃ NO₂ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 73.99%     5.77%        6.16%                                      Found:      73.75%     5.86%        6.03%                                      ______________________________________                                    

EXAMPLE 79-80

The physical constants for Examples 79 and 80 are tabulated in Table 7. The compounds were prepared according to the procedures described in Example 77 and 78.

                  TABLE 7                                                          ______________________________________                                          ##STR152##                                                                    Example                                                                               R.sub.1                                                                              R.sub.2  R.sub.3                                                                            X      Y       mp(°C.)                        ______________________________________                                         79     H                                                                                     ##STR153##                                                                             H                                                                                   ##STR154##                                                                         (CH.sub.2).sub.2                                                                         132-134                               80     H                                                                                     ##STR155##                                                                             H                                                                                   ##STR156##                                                                          ##STR157##                                                                              117-118                               ______________________________________                                    

EXAMPLE 81

In 10 ml. of acetic acid was dissolved in 2.0 g. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine and after adding 1.4 ml. of 30% aqueous hydrogen peroxide solution to the solution while ice-cooling, the mixture was allowed to stand overnight at room temperature. Then, after acetic acid was distilled off from the reaction mixture under reduced pressure, the residue formed was applied to a silica gel column chromatography and purified using chloroform containing 1% ethanol as an eluting solution. Then, the crude crystals obtained were recrystallized from ethanol to provide 1.3 g. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine-1-oxide.

Melting point 217°-218° C.

Elemental analysis for C₁₃ H₁₁ NO₂ S:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Found:      63.80%     4.54%        5.52%                                      Calculated: 63.66%     4.52%        5.71%                                      ______________________________________                                    

EXAMPLE 82

In 4 ml. of glacial acetic acid was dissolved 460 mg. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine and after adding thereto 0.5 ml. of 30% aqueous hydrogen peroxide solution, the mixture was refluxed for 2 hours. After the reaction was over, the reaction mixture obtained was cooled, mixed with 20 ml. of water, and the solid product precipitated was recovered by filtration. The precipitates thus recovered were washed with water and recrystallized from aqueous acetic acid to provide 350 mg. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine-1,1-dioxide.

Melting point 233°-234° C.

Elemental analysis for C₁₃ H₁₁ NO₃ S:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 59.76%     4.24%        5.36%                                      Found:      59.30%     3.77%        5.38%                                      ______________________________________                                    

EXAMPLE 83

After adding dropwise 0.2 ml. of aqueous 30% hydrogen peroxide solution to 3 ml. of glacial acetic acid containing 165 mg. of 5-oxo-7-phenyl-5-hydrothiazolo[3,2-a]pyridine with stirring, the mixture was heated to 80° C. for 24 hours. The reaction mixture obtained was poured into 20 ml. of ice water and extracted thrice each with 10 ml. of chloroform. The extracts were combined, washed with an aqueous sodium hydrogencarbonate solution and then water, and dried over anhydrous sodium carbonate. The solvent was distilled off from the reaction mixture under reduced pressure and the residue formed was applied to a silica gel column chromatography and purified using chloroform as an eluting solution. The eluates containing the desired compound were collected and the solvent was distilled off from the mixture. The solid product obtained was recrystallized from ethyl acetate to provide 30 mg. of 5-oxo-7-phenyl-5-hydrothiazolo[3,2-a]pyridine-1,1-dioxide.

Melting point 204°-205° C.

Elemental analysis for C₁₃ H₉ NO₃ S:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 60.22%     3.50%        5.40%                                      Found:      59.99%     3.56%        5.30%                                      ______________________________________                                    

EXAMPLE 84

In 5 ml. of glacial acetic acid was dissolved 1.2 g. of 3-methyl-5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine and while stirring the solution under ice cooling, 0.67 ml. of 30% hydrogen peroxide solution was added dropwise to the solution. Furthermore, after stirring the mixture for 3 days at room temperature, the reaction mixture was poured into ice water and extracted three times each time with 10 ml. of ethyl acetate. The extracts were combined, washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The solid product thus obtained was recrystallized from a mixture of ethyl acetate and methanol to provide 400 mg. of 3-methyl-5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine-1-oxide.

Melting point 196°-197° C.

Elemental analysis for C₁₄ H₁₃ NO₂ S:

    ______________________________________                                                 C       H         N         S                                          ______________________________________                                         Calculated:                                                                              64.84%    5.05%     5.40%   12.36%                                   Found:    64.65%    5.14%     5.53%   12.12%                                   ______________________________________                                    

EXAMPLE 85

(a). In 5 ml. of acetic anhydride was dissolved 600 mg. of 5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine-1-oxide and after adding thereto a small amount of anhydrous sodium acetate, the mixture was refluxed for 5 hours. Then, after distilling off the reaction solvent under reduced pressure, the residue obtained was neutralized with an aqueous sodium carbonate solution and extracted three times each time with 10 ml. of chloroform. The extracts were combined, washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure.

(b). Then, the residue (2-acetoxy-5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine) thus obtained was mixed with 5 ml. of concentrated sulfuric acid and the mixture was allowed to stand for 30 minutes at room temperature. Thereafter, ice water was added to the mixture and the mixture was neutralized with sodium carbonate and extracted three times each time with 10 ml. of chloroform. The extracts were combined and then the solvent was distilled off under reduced pressure. The residue formed was applied to a silica gel column chromatography and purified using cloroform as an eluting solution. The eluates containing the desired compound were collected, the solvent was distilled off, and the crystals formed were recrystallized from a mixture of cyclohexane and ethyl acetate (volume ratio 1:1) to provide 280 mg. of 5-oxo-7-phenyl-5-hydrothiazolo[3,2-a]pyridine.

Melting point 132°-133° C.

Elemental analysis for C₁₃ H₉ NOS:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 68.70%     3.99%        6.16%                                      Found:      68.44%     3.70%        6.00%                                      ______________________________________                                    

EXAMPLE 86

(a). A mixture of 400 mg. of 3-methyl-5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine-1-oxide, 5 ml. of acetic anhydride, and a small amount of anhydrous sodium acetate was refluxed for 20 hours. The reaction mixture obtained was concentrated under reduced pressure and after adding thereto ice water, was extracted three times each time with 10 ml. of ethyl acetate. The extracts were combined, washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure.

(b). The residue (2-acetoxy-3-methyl-5-oxo-7-phenyl-2,3,5-trihydrothiazolo[3,2-a]pyridine) thus obtained was dissolved in 5 ml. of concentrated sulfuric acid and the solution was allowed to stand for 30 minutes at room temperature. Then, ice water was added to the solution and the crystals precipitated were recovered by filtration, washed with water, and recrystallized from ethyl acetate to provide 175 mg. of 3-methyl-5-oxo-7-phenyl-5-hydrothiazolo[3,2-a]pyridine.

Melting point 168°-169° C.

Elemental analysis for C₁₄ H₁₁ NOS:

    ______________________________________                                                 C       H         N         S                                          ______________________________________                                         Calculated:                                                                              69.68%    4.59%     5.80%   13.29%                                   Found:    69.88%    4.60%     5.72%   13.51%                                   ______________________________________                                    

EXAMPLE 87

In a mixture of 10 ml. of ethanol and 2 ml. of water were dissolved 1.1 g. of 7-methyl-5-oxo-8-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine and 1.6 g. of potassium carbonate and then while stirring the solution, 2.5 g. of methyl iodide was added to the solution at room temperature. After stirring the mixture for 4 days at room temperature, the solvent was distilled off under reduced pressure and then the residue formed was extracted with 50 ml. of chloroform. The extract was washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The residue obtained was applied to a silica gel column chromatography and purified using chloroform containing 2% methanol as an eluting solution. The crystals obtained were recrystallized from ethyl acetate to provide 350 mg. of 1,7-dimethyl-5-oxo-8-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 156°-158° C.

Elemental analysis for C₁₅ H₁₆ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.97%     6.71%        11.66%                                     Found:      74.69%     6.67%        11.74%                                     ______________________________________                                    

EXAMPLE 88

To 5 ml. of methanol containing 320 mg. of 3-methyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine and 600 mg. of methyl iodide was added 1 ml. of water containing 360 mg. of potassium carbonate and the mixture was refluxed for 7 days. After the reaction was over, the solvent was distilled off from the reaction mixture under reduced pressure and the residue formed was mixed with water, alkalified with potassium carbonate, and then extracted three times each time with 10 ml. of ethyl acetate. The extracts were combined, washed with water, and then the solvent was distilled off under reduced pressure. The residue was applied to a silica gel column chromatography and purified using a mixture of methanol and chloroform (volume ratio 1:50) as an eluting solution. The crude crystals obtained were recrystallized from ethyl acetate to provide 120 mg. of 1,3-dimethyl-5-oxo-7-phenyl-1,2,3,5-tetrahydroimidazo[1,2-a]pyridine.

Melting point 145°-146° C.

Elemental analysis for C₁₅ H₁₆ N₂ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 74.97%     6.71%        11.66%                                     Found:      74.69%     6.70%        11.49%                                     ______________________________________                                    

EXAMPLE 89

To 3 ml. of formamide were added 0.3 g. of 1,6-diamino-4-phenyl-2-pyridone and 0.2 g. of 85% formic acid and the mixture was heated to 140°-150° C. for 1 hour. The reaction mixture obtained was cooled and the crystals formed were recovered by filtration. The crystals were then recrystallized from dimethyl formamide to provide 0.15 g. of 5-oxo-7-phenyl-5-hydro-1H-1,2,4-triazolo[2,3-a]pyridine.

Melting point >300° C.

Mass spectrum m/e: 211

Elemental analysis for C₁₂ H₉ N₃ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 68.24%     4.29%        19.89%                                     Found:      67.95%     4.20%        19.78%                                     ______________________________________                                    

In addition, 1,6-diamino-4-phenyl-2-pyridone used as the raw material in this example was prepared by the following manner.

That is, in 50 ml. of ethanol was dissolved 20 g. of ethyl 4-cyano-3-phenyl-3-butenoate and after adding 7 g. of 85% hydrazine hydrate to the solution, the mixture was allowed to stand for 4 days at room temperature. The crystals precipitated were recovered by filtration to provide 10.4 g. of 1,6-diamino-4-phenyl-2-pyridone.

Melting point 237°-238° C.

Elemental analysis for C₁₁ H₁₁ N₃ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 65.66%     5.51%        20.88%                                     Found:      65.70%     5.50%        20.68%                                     ______________________________________                                    

EXAMPLE 90

To 2 ml. of dimethylformamide were added 0.3 g. of 1,6-diamino-4-phenyl-2-pyridone, 0.3 g. of acetylacetone, and 0.1 g. of p-toluenesulfonic acid and the mixture was heated to 110°-120° C. for 15 minutes. The reaction mixture obtained was cooled and crystals precipitated were recovered by filtration. The crystals thus obtained were recrystallized from dimethylformamide to provide 0.28 g. of 2-methyl-5-oxo-7-phenyl-5-hydro-1H-1,2,4-triazolo[2,3-a]pyridine.

Melting point >300° C.

Mass spectrum m/e: 225

Elemental analysis for C₁₃ H₁₁ N₃ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 69.32%     4.92%        18.65%                                     Found:      69.33%     5.09%        18.59%                                     ______________________________________                                    

EXAMPLE 91

To 10 ml. of dimethylformamide was added 0.55 g. of 2-methyl-5-oxo-7-phenyl-5-hydro-1H-1,2,4-triazolo[2,3-a]-pyridine and after adding 0.2 g. of 50% oily sodium hydride to the solution, the mixture was stirred for 10 minutes. Thereafter, 1 ml. of methyl iodide was further added and the resulting mixture was further stirred for 5 hours at room temperature. Then, the solvent was distilled off from the reaction mixture obtained under reduced pressure and then 10 ml. of water was added to the residue formed to form crude crystals. The crude crystals were washed with n-hexane and recrystallized from water with the addition of activated carbon to provide 0.25 g. of 1,2-dimethyl-5-oxo-7-phenyl-5-hydro-1,2,4-triazolo[2,3-a]pyridine.

Melting point 236°-238° C.

Mass spectrum m/e: 239

Elemental analysis for C₁₄ H₁₃ N₃ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 70.28%     5.48%        17.56%                                     Found:      70.31%     5.39%        17.47%                                     ______________________________________                                    

EXAMPLE 92

To 8 ml. of dimethylformamide was added 0.45 g. of 2-methyl-5-oxo-7-phenyl-5-hydro-1H-1,2,4-triazo[2,3-a]pyridine and after adding thereto 0.2 g. of 50% oily sodium hydride, the mixture was stirred for 10 minutes. Then, 0.4 g. of benzyl bromide was added to the mixture followed by stirring for 15 hours at room temperature and then heated tio 150° C. for 2 hours. The reaction mixture was mixed with 30 ml. of water and extracted with 10 ml. of chloroform. The extract was dried over anhydrous sodium sulfate and the solvent was distilled off under reduced pressure. The residue formed was applied to a silica gel column chromatography and purified using a mixture of chloroform and methanol (volume ratio 50:1) as an eluting solution. The eluates containing the desired compound were collected and the solvent was distilled off under reduced pressure. The crystals obtained were recrystallized from aqueous ethanol to provide 0.12 g. of 1-benzyl-2-methyl-5-oxo- 7-phenyl-5-hydro-1,2,4-triazolo[2,3-a]pyridine.

Melting point 216° C.

Mass spectrum m/e: 315.

Elemental analysis for C₂₀ H₁₇ N₃ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 76.17%     5.43%        13.32%                                     Found:      75.92%     5.39%        12.39%                                     ______________________________________                                    

EXAMPLE 93

To 8 ml. of o-dichlorobenzene were added 1 g. of 1,6-diamino-4-phenyl-2-pyridone and 1.2 g. of benzoylacetic acid ethyl ester and the mixture was refluxed for 4 hours. After cooling the reaction mixture, the crystals precipitated were recovered by filtration and washed with ethanol to provide crude crystals. The crude crystals were added to 30 ml. of water containing 1 g. of sodium hydroxide and after stirring for 30 minutes, insoluble materials were recovered by filtration. The insoluble materials were added to 100 ml. of water and stirred at 40°-50° C., whereby they were almost dissolved. The aqueous solution obtained was filtered and the filtrate was acidified with hydrochloric acid, whereby crystals were precipitated. The crytals were recovered by filtration and recrystallized from dimethylformamide to provide 0.23 g. of 5-oxo-2,7-diphenyl-5-hydro-1H- 1,2,4-triazolo[2,3-a]pyridine.

Melting point >300° C.

Mass spectrum m/e: 287.

Elemental analysis for C₁₈ H₁₃ N₃ O:

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 75.25%     4.56%        14.62%                                     Found:      75.08%     4.64%        15.06%                                     ______________________________________                                    

EXAMPLE 94

To 3 ml. of trifluoroacetic acid was added 0.5 g. of 1,6-diamino-4-phenyl-2-pyridone and the mixture was refluxed for 20 hours. After cooling the reaction mixture thus obtained, 15 ml. of water was added thereto and crystals precipitated were recovered by filtration. The crystals were recrystallized from aqueous ethanol to provide 0.5 g. of 5-oxo-7-phenyl-2-trifluoromethyl-5-hydro-1H-1,2,4-triazolo[2,3-a]pyridine.

Melting point 234°-236° C.

Mass spectrum m/e: 279

Elemental analysis for C₁₃ H₈ N₃ OF₃ :

    ______________________________________                                                   C        H            N                                              ______________________________________                                         Calculated: 55.92%     2.89%        15.05%                                     Found:      56.07%     3.13%        15.09%                                     ______________________________________                                     

What is claimed is:
 1. A nitrogen-containing heterocyclic compound of the formula ##STR158## wherein one of R₁ and R₂ is a member selected from the group consisting of a lower alkyl group, a phenyl group, a halophenyl group, and a lower alkoxyphenyl group and the other of them is a member selected from the group consisting of a hydrogen atom, a lower alkyl group and a phenyl lower alkyl group; R₃ is a member selected from the group consisting of a hydrogen atom, a lower alkyl group, a phenyl group, and a phenyl lower alkyl group; X is an imino group, or an ##STR159## wherein R₄ ' is a member selected from the group consisting of a lower alkyl group, a hydroxy lower alkyl group, a cycloalkyl group having 5-7 carbon atoms, and a phenyl lower alkyl group; and Y is a trimethylene group, and the pharmaceutically acceptable non-toxic salts thereof.
 2. A nitrogen containing heterocyclic compound as claimed in claim 1 wherein one of R₁ and R₂ is a member selected from the group consisting of a lower alkyl group, a phenyl group, a halophenyl group, and a lower alkoxyphenyl group and the other of them is a hydrogen atom or a lower alkyl group; R₃ is a hydrogen atom; X is an imino group, or ##STR160## wherein R_(4') is a member selected from the group consisting of a lower alkyl group, a cycloalkyl group having 5-7 carbon atoms, and a phenyl lower alkyl group; Y represents a trimethylene group, and the pharmaceutically acceptable non-toxic salts thereof.
 3. A nitrogen-containing heterocylic compound as claimed in claim 2 wherein R₁ is a hydrogen atom; R₂ is a member selected from the group consisting of a phenyl group, a halophenyl group, and a lower alkoxyphenyl group; R₃ is a hydrogen atom; X is an imino group or an ##STR161## wherein R_(4') has the same meaning as in claim 2, and Y is a trimethylene group.
 4. 6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]-pyrimidine as claimed in claim
 3. 5. 1-methyl-6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine as claimed in claim
 3. 6. A nitrogen-containing heterocyclic compound as claimed in claim 2 wherein R₁ is a hydrogen atom; R₂ is a lower alkyl group; R₃ is a hydrogen atom; X is an imino group or ##STR162## wherein R_(4') is a lower alkyl group; and Y is a trimethylene group.
 7. 8-methyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine as claimed in claim
 6. 8. 1,8-dimethyl-6-oxo-1,2,3,4,6-pentahydropyrido[1,2-a]pyrimidine as claimed in claim
 6. 9. A nitrogen-containing heterocyclic compound as claimed in claim 2 wherein one of R₁ and R₂ is a phenyl group and the other is a lower alkyl group; R₃ is a hydrogen atom; X is an ##STR163## wherein R_(4') is as defined in claim 2; and Y is a trimethylene group.
 10. 1,7-dimethyl-6-oxo-8-phenyl-1,2,3,4,6-pentahydropyrido[1,2-a]-pyrimidine as claimed in claim
 9. 11. An analgesic anti-inflammatory composition comprising an effective amount of a compound of claim 1 and a pharmaceutically acceptable carrier or excipient.
 12. A composition as claimed in claim 11 wherein said excipient is selected from the group consisting of calcium carbonate, calcium phosphate, starch, sucrose, lactose, talc, magnesium stearate, gelatin, polyvinyl, pyrrolidone, gum arabic, sorbitol, microcrystalline cellulose, polyethylene glycol, silica, and sodium lauryl sulfate.
 13. A composition as claimed in claim 11 which is in the form of an aqueous or oily suspension, a syrup, or an elixir.
 14. A composition as claimed in claim 11 which is in the form of a suppository.
 15. A method of inducing an analgesic or anti-inflammatory effect comprising administering an effective amount of the composition of claim
 11. 